Lynxmotion robot arm ALD5 shakes

ALD5 is constantly shaking, mainly elbow and shoulder. I just installed a new SSC-32U.

@eanthony Welcome to the RobotShop community.

Can you confirm you had the AL5D working before correctly and the ONLY change you made was the SSC-32U? How are your controlling it?

Normally if the arm shakes it is because of the following reasons:

  • Incorrect power supply (low current or wrong voltage).
  • Bad wiring (or one of the servo extension cables is loose)
  • Steps 4 and / or 10 are over-tightened and need to be loosened: AL5D Arm Assembly Instructions Rev. 2.1

Can you provide a short video showing what’s happening, as well as some clear photos of the connections to the SSC-32U?

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OK I have included pictures and videos. I have used the power supply and laptop successfully with other arms, and the arms were purchased assembled for PLTW classes. I can’t verify 100% the arm was working well before the old board failure (usb port broke off). I tried a number of different combinations of starting up and calibrating with no improvement.

video for previous reply

@eanthony at 0:07 in the video when you plugged in the USB there seemed to be a spark - that should absolutely NOT happen. Physically unplug the barrel connector (removing power) and check the wires going to the screw terminals for any loose wires which may be in contact with each other, the board etc.


Your connections between the servos and the SSC-32U seem fine and I cannot spot anywhere where the servo extension wires are not plugged in correctly. This really does seem to be a power issue. If the arm (or any electronic device for that matter) behaves like that, unplug immediately.

If you don’t spot any loose wires etc. which would explain this, remove the wires from the screw terminals, trim a little off and put them back in. Unplug all but ONE servo and see what happens when you turn the power ON without the USB in place. Let’s eliminate any software issue.

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OK I will try that and provide an update, I don’t believe it was a spark you saw though, I’m pretty sure it was the light flashing on the board, which it does when I plug in the usb. Maybe the camera angle made it look like a spark.

It also sounded like a spark…

If the electronics are (theoretically) all working, the next step is to check the software, and instead of using FlowArm, try with:

However, it really does seem to be an electrical issue…

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Here is another video. You can see the base has a slight wiggle, but the problem was servo in port 2. I undid and reconnected everything between the board and servo, and it seems to be good now. Thanks!